What's Digging Up Your Lawn? Ontario's Late-Summer Grub and Skunk Problem, Explained

Quick answer: If your Ontario lawn is being dug up overnight in late August or September, the animal is a symptom and grubs are the cause. Skunks and raccoons tear turf apart because there is a protein-rich food source three centimetres beneath it. Removing the animal changes nothing — a new one finds the same buffet within days. Deal with the grub population and the digging stops on its own. Call (705) 302-1887 or take the free quote quiz.

The mistake almost everyone makes

You walk out on an August morning and a strip of your back lawn looks like someone went at it with a garden fork. Chunks of sod flipped over. Small conical holes punched through the turf. It was fine yesterday.

The instinct is to declare a skunk problem and start looking for ways to get rid of the skunk. That instinct will cost you a season.

Skunks and raccoons are not digging your lawn because they like your lawn. They are digging because late August is when white grubs — the larvae of Japanese beetles and European chafers — are large, plump, and sitting in the top few centimetres of soil feeding on grass roots. To a skunk in the weeks before winter, that is the highest-calorie meal available within a night’s walk.

Trap the skunk and relocate it, and Ontario’s rules require release within 1 kilometre of capture anyway. Meanwhile the grubs are still there, still broadcasting, and the next raccoon along the fence line will find them by the weekend. The animal is downstream of the actual problem.

How to tell what is digging

The damage pattern names the animal, and it takes about a minute to read.

Skunks make small, neat, cone-shaped holes roughly three to eight centimetres across, punched straight down, usually scattered in loose clusters. Skunks have a precise nose and dig where they smell an individual grub. Damage appears overnight and is often accompanied by a faint musk smell near a deck or shed.

Raccoons do something visibly different. They have hands, and they use them — turf gets rolled back in sheets, like carpet peeled off a floor, sometimes in strips a metre long. If your sod is flipped over in intact pieces, that is a raccoon.

Grubs alone, without any animal, show up as irregular patches of yellowing or dead grass that feel spongy underfoot. The diagnostic test: grab the affected turf and pull. If the grub population is heavy, it lifts like a loose rug, because the roots have been eaten away beneath it.

A few small holes and no turf damage may be something else entirely. Ground-nesting yellowjackets, still very active this time of year, use a single small opening in a lawn or bank with steady insect traffic in and out of it — a completely different problem with a completely different and considerably more urgent answer. Our guide to ground-nesting yellowjackets in Ontario lawns covers how to find that nest and deal with it safely.

Why this happens now, and worse in some neighbourhoods

The timing is not random. Japanese beetle adults were flying and laying eggs in July across the GTA and Simcoe County. Those eggs hatch through August, and the larvae feed heavily through late summer into fall before burrowing deeper as the soil cools. Late August to early October is the exact window when grubs are big enough to be worth digging for and still shallow enough to reach.

Two things concentrate the damage. Irrigated lawns get hit harder, because moist soil is where beetles prefer to lay — a well-watered lawn in a dry August is a target. And properties backing onto a ravine, park, golf course or open field have a steady supply of both beetles and the animals that eat their larvae, which is why the same Barrie and Pickering streets see it year after year while the next block over does not.

If you saw Japanese beetles skeletonizing roses, linden or grape leaves earlier this summer, you were watching the parents of the grubs currently under your lawn. Our Japanese beetle guide covers that half of the life cycle and why the spring treatment window matters.

What actually works

Confirm the grub count before treating anything. Cut three sides of a 30 cm × 30 cm square of turf, about 5 cm deep, and fold it back like a flap. Count the white C-shaped larvae. Fewer than five in that square is a healthy lawn that does not need treatment — some grubs are normal. Ten or more means a population heavy enough to both kill turf and attract diggers. Fold the flap back and water it in. This one test prevents most of the wasted money in lawn care.

Match the fix to the season. Beneficial nematodes — microscopic organisms watered into the lawn — are the standard reduced-risk option and are most effective when grubs are small and the soil is warm and moist, which is why late summer and early fall is the window people target. They need moist soil to move through and must be watered in properly; applied to dry ground in full sun, they do nothing.

Repair before you reseed. Tamp flipped sod back down and water it. Turf with intact roots often re-establishes. Overseeding bare patches in early September takes advantage of the best grass-growing conditions of the year.

Stop feeding the rest of the yard. Secured bin lids, no fallen fruit left under trees, no pet food outside overnight. A lawn full of grubs plus an open green bin is a property no raccoon walks past.

Do not seal under a deck or shed until you are certain it is empty. Skunks den under low structures, and sealing an occupied space in September creates a far worse problem than the one you started with.

The wider point about the perimeter

A grub-driven digging problem is a good illustration of something we see constantly: the visible pest is rarely the whole picture. The same late-summer conditions that put grubs under your lawn are putting earwigs and ants against your foundation, drawing wasps to anything sweet, and starting the rodent push toward your garage.

Treating one of those in isolation, once, is how a property ends up on a permanent treadmill — a call in August, another in October, another next May.

Every Sani IQ service starts with a $95 professional inspection, credited in full when you book the treatment. For a general exterior insect issue, General Insect Control starts at $395 exterior or $475 interior and exterior, with a 60-day guarantee.

But the honest recommendation for a property that has grub-driven lawn damage is not a single visit. It is Insect Control at $845 per year, which puts your perimeter on a scheduled program across the whole season rather than reacting to whatever surfaces next. For properties that want the rodent and wildlife pressure covered on the same schedule, Essentials at $1,195 or VIP from $1,395 extends that to year-round protection on the entire envelope of the building.

The arithmetic is straightforward. Re-sodding a damaged section of lawn, plus two or three reactive one-time treatments across a season, generally costs more than a year of protection — and leaves you doing it again next August. Full details are on our plans and pricing page, and our residential pest control services page covers what a scheduled program actually includes.

Sani IQ is owner-operated, licensed under the Ontario Pesticides Act and registered with the MECP, BBB Accredited, and carries $5 million in liability coverage. Our technicians are employed by us, licensed and background-checked — never subcontracted. We hold a 5.0 rating across 126 Google reviews.

Call (705) 302-1887 or take the free quote quiz and we will come back with a plan for your property. For identification help on anything else showing up this season, the Sani IQ pest library is a good place to start.

Frequently asked questions

Why is something digging up my lawn at night in Ontario? Almost always grubs. From late August through fall, white grubs feed near the soil surface, and skunks and raccoons dig to reach them. The digging follows the grub population, not the animal.

How can I tell if it is a skunk or a raccoon? Skunks punch small cone-shaped holes a few centimetres across. Raccoons roll turf back in sheets, using their front paws. Peeled-back sod means raccoon; scattered small holes mean skunk.

How many grubs are too many? Count them in a 30 cm × 30 cm square of turf. Under five is normal and needs no treatment. Ten or more is a population heavy enough to damage the lawn and attract diggers.

Will getting rid of the skunk stop the digging? No. Ontario requires live-captured wildlife to be released within 1 kilometre of the capture site, and even if the animal stayed away, the food source is still there for the next one. Address the grubs and the digging stops.

When is the best time to treat grubs in Ontario? Late summer into early fall, while larvae are small and near the surface and the soil is still warm and moist. Once they burrow deeper for winter, treatment effectiveness drops sharply until the following season.

Will my lawn recover on its own? Lightly damaged turf with roots intact usually recovers if you tamp it back down and water it. Areas where roots have been eaten need overseeding — early September is the best window in Ontario for that.

Is grub treatment safe around pets and kids? We use reduced-risk products and licensed application methods under the Ontario Pesticides Act, and your technician will give you specific re-entry guidance for anything applied to your property.